Unloader for air-compressors.



W. H. CALLAN 6L Gf). MACFADDEN. uNLoADm ppn Am coMPHEssoRs.

` AFPLICATWNMFILED MAR. B. 19,15-

'1 ,224,272, v Patented May 1, 1917.l

` 2 SHEETS-SHEET 1- 4 l w. H. CALLAN & G. V1I MACFADJEN..

UNLOADER FOR AIR COMPRESSOIS.

APPLICATION FILED MAR. a. |915.

2 SHEETS-SHEET 2* y K 11111111111111111711//1/111lll/11 11.111111/ m if) wh 1' i w UNITED STATES PATENT oEEroE.

WILLIAM H.y CALLANAND GEORGE J. HAUFADDEI, "OF FRANK LIN, PEHNBYLVANIA, ASSIGNOBS T0 CHICAGO PNEUMATIC '1300L COIPANY, 0l' UHICAGO, ILLINOIS, A.

VCORPORATION 0F `NEVI' JERSEY.

UNLOADEB FR AIBCQI-PBESBOBS.

To all whom it may concern:

lie it known that we, WiLLiAM ll. ('.ALLAN and (iconos il. Maelfann'izx, citizens of the United States, residing at Franklin, in the county of -Venango and State of Pennsylvaniiu have invented certain new and useful 'Improvements in Unloaders for Air-Coiii pressors, of which the following is a specification.

.()ur invention relates to an unloaderI for air compressors and the object thereof is to 'provide a simple, oliieient and reliable device of this kind', which is i'zharacterized more particolari) by the employment of a jvalve irovided with two separate seats for contro ling openings of differential a'ea for the loaded and unloaded position of the valve. with the resultthat the valve is positive in its action in both opening and closing,.there being no position or condition of hesitation of the valve between oi'iening and closing positions, ln prior devices when a certain point is reached 'in their operation at which time the supply and the demand becomesubstantially' equal,l they will hesitate between loading and ulnloading conscquently giving great trouble and annoyance, whereas in our device there being two different areas exi'iosedin the two positions, there is no possible chance for hesitation hetween loading and unloading and the valve will therefore move positively against one Beat or `the-other at all times. (lther 'lcatures of novelty and utility in in v uuloadcl will he apparent from the description lierein affter giveni In the drawings'Figure l is an elevation of a. part of a eoi'ni'iressor showing a n inlet valve and our unloader in sei-tion; Fig. a

central longitudinal section of the unloadinon a larger scale than shown in Fig. l and illustrating the valve in unloaded position; Fig. 3 central longitudinal section o-.f a

`modified form of unloader illustrating;r the 'valve in loaded position; Fig. 4 a top plan View of the valve, of Fig. i and Figera cen-. `trai longitudinal lsectionof one end ol an Vother modified form of unloader.

(`)ur invention may be'en'ibodicd in struc- -tures of somewhat different form and arn rangement' and in the present. instance we have illustrated three different' forms, all of which have substantially the samemodeof operation and.l accomplish lthe same result.

Speccation o! Letten Patent.

Referring to the embodiment of our in- 5 5 vention as illustrated in Figs. l and 2 the unloader comprises a shell or casing of sii-itable forni and 'dimer sions and inclosing the unloader valvelwhici is adapted to control the admission of the air pressure from .the

initting the compressor to run or operate 6'5 without compression In the present instance the iinloader consists of a shell or casing 1 having at its' upper -end (assuming that the unloade-r is )laced in a vertical positlon) a chamber 2 and at its lower end a 70 chamber 3, 'the forirer being of thel larger diameter. The upper ,end of the chamber isi closed by a hollo'v screw plug or cap 4 y having an interior iressure chamber 5 in which the receiver pressure is always present inasmuch as such chamber communicates' therewith tl'irough tl e pipe (i leading from. the receiver through Lhe top of the cap. i A seat 7 is formed in the chamber 2 at the junction thereof witi the other chamber 5l 80' ,and' another seat 8 formed at the lower end of the cap 4.

lioth if-these seats are circular and the seat i is somewhat larger in diameter than the oti er seat for the purpose and with the result hereinafter explained.'85`

The iiriloadcr valve i) is in the form ot' a plaieI or disk whose` opposite faces forni scats adaptcdio coi ierate with the seats T and 8, thc valve being upon one scat in the unloaded andon the other in the loaded position thereof.

Referring to the )articular construction shown in Figs. l and .`.,the unloading valve is mounted -to slide lipon the exterior walls of the cap 4 anilto tl is end thc valvcis pro- 95- vided with marginal flanges 10"'which su'rround said walls and are ,guidi-d thereby in the vertical niovemeiitsof the valve. This flange is provided with one or a series of openings or ports ll, through which the air vfrom the receiver passes into lchamber 2 when the valve is in open or unloaded position as indicated 'in l* ig. 2 2, 'the air first passing from the chaiiibsv r o past the valve seat.

8 and throughthe ciicinnferential groove 12105 'before passing throui'h'theports l1.

The unloading val le is held to its loaded or. working position :ihown in Fig. 1 with a.

.Pa rented May 1, 1917.

Application led Iarch 8, 1915. Serial No. 12,828. i i

' screw 16 instance act upon -respectively, one

cylinder pro c onto the block 20.

predetermined pressure by means of a plunger 13 whose head or upper end has a point bearin contact with the under side of the unloa er valve. This plunger is springpressed upwardly by means of the coiled spring 14: whose upper end bears against the head of the plunger and whose lower end bears against a washer 15 which in [turn bears against the inner end of the adjustm screw 16 which screws into the lower end o the casing 1. The tension of the'spring can be regulated :or adjusted by screwing the in orout accordingly asrequired, the same being held in ad'usted position by means of the -jam nut 1 The adjusting screw is hollow in order to receive the plunger 13 and thereby serve as a guide therefor. The chamber 2 is connecte by means oi the pipe connection .1.8 to fluid :pressure operated mechanism which in the present the suction, or inlet valves of .which together. with said mechanism is shownin section in Fig. 1. .This mechanism consists of a piston 1 9. operatin in a chamber or cylinder formed in a bloc or plug-'20 screwing intothe upper end of the casngil of the inletvalve, the -Jj-"co unica'ting with the amber 22 ormed by a c 'ap 23 screwing A branch pipe24 leads through the'cap 23 to the chamber 22m the air pressureagainst the piston 19 to forcefthe latter downwardly.

` A slmilar' branch `pipe suction valve structure asV The piston 19 acts v'depending arms 25 :downwardly by, the

24 leads touthe other shown in Fig. 1. against a serles of which when` moved iston bear against the suction valve-.26 hol in g it open. as long'as the-piston 19 is acted upon byy the air pressure. As a result the compressor will oper# ate vwithoutco'mpression inasmuch-as the air -I reached la predetermined `will blow in and out throu gh the inletopenings during the reciprocations of the piston' (not shown) of the compressor. l s in' the receiver has When the pressure .degree such preslsure which is always present 'in the. chamber 5' acts to move the valve '9Q from its 'inner seat 8 by. overcoming theresista'nce of the spring 14 and to seat -it on its-outer seat 7 .The air will thereupon -owfrom chamber 5 through the ports 11 to the 'chamber 2 from y whence it passes vfrom the pipes 18 and 24 to I forced downwardly the chamber 22. The piston'L 19will now be and the inlet vvalve 26 will be held open. This represents the unloaded positionof the parts.

lVh'en the pressure in the receiver and pipe connection 6 have been certain predetermined degree the spring l14:'-

will overcome the-pressure exerted on the top of the valve -and will raise lit-from its seat-7 and seat v1t upon the other 'seat 8. The air which would otherwise' beitrapped is thus exhausted ,erted upon the, top area of the valve is tension 4of .the spring with itsl mar 'the plunger ,13 isdis d with and a tubuf orme in the pipes 18 and 24 and the will now be released therefrom by' ow` from the chamber 2 past the seat` 7, throii the chamber and out through the out t. Aports 27 in the casing 1. This represents 70 the normal or loaded osition of the parts. It, will be understood t at when the pressure through the ports 27 thev fluid pressure mechanism is ofcourse re' lieved and restored to normal position by means of the coiled 'spring 28 .acting to raise the piston 19 and its connected parts to normal position shown in Fig. 1,'l thereby removing the interference -with the fun c" tions of the inlet valve. i0 The diameter of the seat 8 is somewhat?l less than the other seat 7 with the result that the unloading valve when unloaded is; unbalanced to the extent of the difference in the areas less the added tension of the '35 spring 14 vwhen the valve is 'on the yseat 7, with the result that the valve is held tightlyl upon such latter seat until the pressure rfrom the receiver, that is the pressure ex- 90. reduced to adenite point whereupon the overcomes said pressure, unseating the valve at the seat77' and seating it upon the other seat 8 as above explained. The innerend of the oa is inthe form 'of a tubular extension which' not. onl forms vthe 'seat 8 as described but also orms a means for guiding the valve in cooperationv 'nal flange. The construc-v tion is 'such t at the ports '11 are always open. In 'the present instancey the seat 8 is formed by cutting awayv the outer' corner.)v ofthe innerend of said tubular'extension leaving the'seat 8 projecting so as to be con`7 195 tacted by the top face of the valve.

Referrin 'tothe modification shown in Figs. 3 an 4, the main arts 'are the same withthe exception that t e valve is guided both on the outside'and inside of thetubu- `la'r- -extension of the .cap but mostly on the inside inasmuch as the marginal iange `10 of the valve is shorter `than the --lange 10; of the form .shown in Figs; 1 and 2. To provide for lthe inside ide the 'valve is 11e 'provided with an upwar yfextendin tuhular portion 9F having'a series of radial ribs 9" adapted to fit and slide on the-inner wallsof the tubular extension of the cap L In addition the plun r 13 ha 'e portion 13* --120 extending throng the valve into thev other respects the construction is 'substan tially the sameas that shown in Fig. 2'. In Fig. 5 we have shown still anoglrirer modified form 'of construction which is' s -V lar to that of Fig. 2 'with the exception that lar extension'. 29`is dv onor secured to the under side of the valvel adapted to slide 1 30 lit,

l is assist inguiding the v the upwardly-exvalve. f Moreover, i bears directlyV againstthei valve. The tu ular extension 29 is provided with one or more portsor passages 8,11 vfairy'permitting the exhaust of the air from the 'fluid pressure operated m h anisrn when the V,valve is on its 'seat 8. lVhile in the drawings we have shown the unloadin valve covering the two suction valves o "the same cylinder it will be underv ,stood that this valve may be utilized to con trol-,all of the suction valves of a multistage compressor by providing the fluid pressure rated Imechanisms for actuating the suction valves gf the other cylinders and by with the connecting :auch mechanisms pi I15,

ec i? if in the chamber to .valve inconnection' with tending Bange 10 of the. in this instance the sprin 1. A controlling device for air compressors comprising a casing adapted to lcommunid y cate respectively with a supply of air under pressure and with a. fluid pressure operated 25V unloader mechanism, said casing also having an outlet to atmos here, two opposed seats in f said casin ,oneo which-communicates with said supp and the other with said outlet,

` a valve in ucnced constantly by a predeter mined pressure and operating between said seats and adapted tobe seated upon one seat or the other, and means vbeyond'the Avalve seat communicating withthe air supply for throttling the passage from'said seat.

2. In a d vice of the class described, the combinationl of a casing having opposedvalve seats" rein, a valve movable between and adapted to engage said seats, a conn'eo. tionfrom one of said seats to an -air receiver, connections from the other said seat to exhaust?a connectionfrom saidV casing to a fluid Ipressure actuated unloader mechanism and means beyond said valve seat for throttling the` air coming from the receiven' 3. Acontrol comprising acasing, a connection from said casing 4to a-reiverfa valve seatcontrolling said 'connectiom an outlet, opening from the casing to the atmosphere, a valve wat controlling said outlet, a connection fromV said casing to a fluid pressure operated unloader mechanism, a valve -coperating with said valve sentito alternately close the connec- 'tion from '-receiver andthe outlet respectivelyr td'lsai `fluid operated unloader mech# y aniSm and means coperating with the valve and the first said valve scatto throttle the 'flow of air from the receiver tothe interior' i of the -casing. l y 4. A controlling device for air compres 4,sors comprising a casing having a'tlibular portion communicating with a receiver and formed 'at one end with nec-tion fromsaid casing to a Huid pressure 65, operated unloader. mechanism, said casing- 'imma v l passages ling device forair compressors a valve seat, a con also having an outlet to thev atmosphere, a q eond valve seat op posite the first said seat,l

.a ``valve arranged between said seats and adapted to coperan with the same alter' nately, means for exerting a predetermined .I pressure u n the'valve to normall Yhold it upon the rst said lest, said valve `aving a sliding engagement with said tubular portion of the casing vherehy the air passing from the receiver th rough the first said valve seat is throttled.

A controlling device for air compressors 'comprising a ca `sing having a connecti'on for a'iluid pressurs unloader mechanism, a connection rom said casing to a receiver, a valve Seat controlli ig the latter connection, the casing alsov hai ing an outlet to the at` mosphere and a' valve seat controlling said outlet, the two valie seats being in opposed positions, a valve coperating with the valve seats to alternately close the same, a flange on the valve having; sliding connection with the first said valve seat and openings in the flange of smaller' total capacity than the openingnin the 'val :e seat whereby the flow of air t o ugli'the seat is throttled.

6. A. controlling device for air compres sors comprising a Casin adapted to communicate respectively wit a supply of air under pressure and u ith a fluid pressure operated unloader mechanism, said casing also having an outlet to the atmosphere, two opposed seats in said zasing, one of which communicates withrsaid supply and the other with said outlet, whe former being of less 1;,3 area. than the other,` a. valve @operating alternatively with the two valve seats,`and means for forcing,l such valve against-the seat communicatin g with the air supply and arranged to communicate with the )30, lv alve seat commu aicating lwith the supply when said seat is open, of restricted total area comparedto :1a-id seat.`

7. A controlling' device for air compres, sors comprising'a c portion communie iti ng with 'a` source 4of air under pressure aid rovided at one end with a valve seat, saidpcasing also having a communication w th a fluid pressure oper- .ated unloader me :hanism and an outlet to the atmosphere, s second seat larger than the iirst named seat and arranged opposite thereto and betwec n said' communication and said outlet, a val v e arranged betweenaid seats-and adaptel to be seated upon one V Seat or the other,

and means for exerting a predeterminedl pressure upon the valve t0` normally hold it upon said smaller seat, said valve being of a diameter greater than i that of said sma'. ler seat, said valve being 125 d be' guided by said mounted toslide upon an tubular portion.`

8. A controlling device for air compressors comprising :i casing having a tubular portion communicating with aging having a tubular 113 asource of air 131.`

under pressure and with a valve seat, said casing also having a communication with a fluid rssure open ated unloader mechanism and)A an outlet to the atmosphere, the first named seat and arranged opposite thereto and between said communication and said outlet, said seats and adapted to be seated upon one seat -or the other, and `means for exerting a predetermined pressure upon the valve to normallyhold it upon said smaller seat, said valve being of substantially disk form with a marginal fiange slidin upon the louter walls ofsaid tubular portion.'

9. A controlling device for air compressors comprising a casing having a tubular portion communicating with `a source of air under pressurev and provided at one end with a 'v alve seat, said casing 4also having a communication with a fluid pressure operated lunloader mechanismand an outlet to the atmosphere, a second seat larger than the first named seat and arranged opposite thereto and between said communication and said out-let, a valve arranged between said seats and one seat or the other, and means for exerting a predetermined pressure upon the valve to normally hold it upon said smaller seat, said valve being of substantially ldisk form with a marginal flange sliding upon the outer walls of said tubular portion and hav- I sors comprising a casing having a tubular4 I first named and said ou'tlet, a

' 'mg a passage for the air controlled by the 35 va ve v'10. A controlling device for' air compresportioncommunicating with a source of air under pressure and provided at one end with .a valve seat, said casing also havlng a com-V munlcation lwith a Huid pressure operated unloader' mechanism and an outlet to the atmosphere', a second seat larger than the seat and arranged Aopposite between said communication valve arrahged'-between said seats and adapted. to be 'seated upon thereto and rovided at one end.

a second seat larger than y a valve arranged between.

a ca

a tu ular portion extending into the shel adapted to be seated upon .ing with both of them, provided with a marginal--fiange V10 sliding p Lemma 11. A controlling device` for air compressors comprising a shell having an open end,

removabl secured to the shell havin and communicating with a source of air under pressure," the, inner end of said tubular portion providing a valve seat,vsaid shellalso having communication' with a fluid pressure operated unloader mechanism and an outlet to the atmosphere, said shell havingra seat arranged'opposite the other seat and between said communication Aand said outlet, the latter seat being the larger, land a valvejarranged between and cooperating with said seats and normally held upon the smaller seat with a predetermined yielding pressure, said valve having a cylindrical marginal flange sliding upon the outer wall of said tubular openings therei'n. l

12. `A controlling device for sors comprising a casing 1 having chambers 2 and 3 and outlet port 27 and also having la seat 7, a cap'4 removably' secured to said casing `and having a tubular portion. ex tending into chamberv 2,. the inner end of which provides a 7, and anvunloader valve 0 ojf disk form ar'- ranged'between the two seats and coperatsaid valve being on said tubular extension 11l closed when the valve is-on seat 8 and opened when the valve is on seat 7. i WILLIAM lL CA LLAN.

y GEORGE J, MAGFADDEN. i 4Witnesses: 'v WAYNE W. BLAKELEY,

Les H. WRIGHT.

and vhaving ports air compresseat 8 smaller than seatportion, and formed with 

